This invention concerns the veneer production sector; in particular, it concerns a method for producing sheets of precomposed wood with differentiated porosities, as well as the sheets of wood thus obtained, which can be used as veneers for covering furniture and the like.
As is known the growing demand for natural wood veneers and the decreasing availability of valuable species of timber, has led to the development of methods for producing precomposed wood veneers, obtained from a given species of wood, of lesser value and widely available, for the purpose of producing veneers made of precomposed wood imitating veneers of more valuable species of wood.
The known methods start substantially from a single type of wood sheet which, after being suitably colored or dyed, is then used for reconstructing an artificial trunk or block of precomposed wood, by glueing together sheets of differently colored and/or differently dyed wood, so as to imitate as closely as possible the patterns of the various types of grain in the wood.
All the known and currently used methods are therefore based on the common principle of imitating the grain of the wood merely by means of the differentiated color effect of the basic sheets of wood used. Special effects achieved by shading the color may improve the degree of imitation of the grain, however the sheets of precomposed wood and the veneer obtained from them are subject to limits due to the actual methods used; these limits are consequential to the obvious forming of a grain pattern achieved merely by means of color. Consequently, with the known methods, the end product which is obtained reveals its non-natural origin, is easily recognizable from that obtained from a natural log of wood, and is consequently unappreciated or ignored due to its lesser value, by certain categories of furniture manufacturers.
The general scope of this invention is to provide a method for producing sheets of precomposed wood, in such as way as to imitate as closely as possible, not only the typical pattern of the grain of sheets of natural wood, but even the fibre structure of the wood which is to be imitated, with effects that can without a doubt be defined as remarkable. According to this invention, the problem was viewed from a completely opposite standpoint, never as yet taken into consideration, and precisely by the fact that the grain of natural wood is due not only to the alternation of the various fibrous rings of annual growth of the tree trunks, but also by the fact that there are two fundamental layers in each annual growth rings, one richer in fibre than the other and, therefore, with a more homogenous appearance and structure, and very often differently colored, so as to show different degrees of porosity in the structure of the wood, in the different seasons of annual growth.
This differentiation between the layers of seasonal growth, in each annual growth ring, is accentuated when the sheets of wood are varnished, by the greater or lesser penetration of the varnish into the layers with different structures and porosities.
A further scope of this invention is to provide a method for producing sheets of precomposed wood, designed to imitate veneers of natural wood, which ensure constant repeatability of the patterns of the grain, unlike natural veneers where, due to the differences between one log and another, and in the same log itself, it is not always possible to obtain sheets of veneer with the same pattern; a fact which makes veneers obtained from sheets of precomposed wood even more qualifiable in that the repeatability of the pattern makes them very practical for use in the mass-production of furniture. It is pointed out that, for the scopes of this description, the term "sheet of natural wood" is used to indicate a sheet of wood obtained directly by rotary cutting or shearing a tree trunk, and that the term "sheet of precomposed wood" is used to indicate a sheet of wood obtained by shearing from a block made up of sheets of wood suitably glued and pressed together.